Various software applications and other tools facilitate the creation of media content such as web banners, site openers, showcase sites, and concept pitches. An “action” is something that happens when content runs, including what a page or object within a page does. An action can describe motion (move, face, etc.) or interaction (play, go to link, etc.). Media content can involve various types of objects, including displayed objects such as squares, circles, other shapes, buttons, text, web links, images, movies, and objects that are not displayed.
Some media content development tools display a development canvas that provides a visual preview of the content being developed and allows adjustment of the size or position of a displayed object. However, generally, such tools require significant user effort, particularly in defining movement, interactivity and other actions, which are typically user coded. While such tools are often powerful, robust, and useful, they may be ill-suited for some users, such as those unfamiliar with the particulars of the development environment, coding syntax, and parameters, including the available objects, actions, and triggers. For example, timeline features in existing tools tend to provide frame-based features that are both granular and powerful but that generally fail to provide mechanisms for observing and controlling actions as whole units and instead tend to present and control content as granular changes to properties over time.